Liaoning Key Laboratory for Biological Invasions and Global Changes, College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, China.
Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia.
Physiol Plant. 2022 Jan;174(1):e13637. doi: 10.1111/ppl.13637.
High-phenotypic plasticity has long been considered as a characteristic promoting exotic plant invasions. However, the results of the studies testing this hypothesis are still inconsistent. Overlooking the effects of species resource requirements and environmental resource availability may be the main reasons for the ambiguous conclusions. Here, we compared phenotypic plasticity between five noxious invasive species with different nutrient requirements (evaluated using the soil nutrient status of their natural distribution ranges) and their phylogenetically related natives under five nutrient levels. We found that species with high-nutrient requirements showed greater plasticity of total biomass than species with low-nutrient requirements, regardless of their status (invasive or native). Invasives with high-nutrient requirements had greater growth plasticity than their related natives, which may contribute to their invasiveness under high-nutrient environments. However, compared with the related natives, a higher growth plasticity may not help exotic species with low-nutrient requirements to invade nutrient-rich habitats, and exotic species with high-nutrient requirements to invade nutrient-limited habitats. In contrast, invasives with low-nutrient requirements exhibited lower growth plasticity than their related natives, contributing to their invasiveness under nutrient-limited habitats. Functional traits showed growth-related plasticity in only 10 cases (3.8%), and there was no functional trait whose plastic response to soil nutrients was beneficial to exotic plant invasions. Our study indicates that low-growth plasticity could also promote exotic plant invasions, high plasticity may not necessarily lead to invasiveness. We must test the adaptive significance of plasticity of functional traits when studying its biological roles.
高表型可塑性长期以来一直被认为是促进外来植物入侵的一个特征。然而，检验这一假说的研究结果仍然不一致。忽视物种资源需求和环境资源可利用性的影响可能是结论模棱两可的主要原因。在这里，我们比较了五种营养需求不同（通过评估其自然分布范围内的土壤养分状况来评价）的有毒入侵物种与其亲缘本地种在五种养分水平下的表型可塑性。我们发现，高营养需求的物种比低营养需求的物种表现出更大的总生物量可塑性，而不论其状态（入侵或本地）如何。高营养需求的入侵物种比其亲缘本地种具有更大的生长可塑性，这可能有助于它们在高营养环境下的入侵。然而，与亲缘本地种相比，较高的生长可塑性可能无助于低营养需求的外来物种入侵富营养生境，也无助于高营养需求的外来物种入侵营养受限生境。相比之下，低营养需求的入侵物种表现出比其亲缘本地种更低的生长可塑性，这有助于它们在营养受限的生境中入侵。功能性状仅在 10 种情况下（3.8%）表现出与生长相关的可塑性，并且没有功能性状对土壤养分的可塑性反应有利于外来植物的入侵。我们的研究表明，低生长可塑性也可以促进外来植物的入侵，高可塑性不一定导致入侵性。在研究功能性状的生物学作用时，我们必须检验其可塑性的适应性意义。
